The present disclosure relates to geology formation analysis. More specifically the present disclosure relates to an apparatus for measuring trend and plunge of a lineation observed on geologic foliation or bedding.
Structural geology includes the observation and measurement of rock plane and lines and uses measurements of present day rock geometries to determine the history of deformation in various geologic strata.
For a plane a direction of an intersection defined by a bedding plane and a horizontal plane is referred to as strike and an angle between the bedding plane and the horizontal plane is referred to as dip.
In field work, strike is typically measured by supporting a side surface of a Brunton compass on a bedding plane and leveling the compass to read a magnetic North direction of the compass relative to the bedding plane. Dip is measured by locating an inclinometer in a direction perpendicular to the horizontal plane to read an angle of dip. Strike is scalar and dip is a vector.
Linear structural features within rock formations are known in structural geology as lineation. Lineation is measured in terms of trend and plunge. Trend is the bearing of a line from magnetic North of a linear geologic feature measured in a direction in which the line is inclined downward. Plunge is the degree of inclination of the linear feature. Together trend and plunge define a line vector of a geologic line in a formation. If the lineation has a very small size it is difficult to accurately measure trend and plunge.